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Regex Isn't Hard (2023)
61–70 of 109 posts
Re: Regex Isn't Hard (2023)
#62Earlier quoted context omitted.
lol really? Why not? Is that true for all encodings? Is it a bug or a feature? What about a simple character set like gsm-7 Swedish?
The author says “any lowercase character” but they mean “any character between the character ‘a’ and the character ‘z’”, which happens to correspond to the lower case letters in English but doesn’t include ü, õ, ø, etc.
> but they mean “any character between the character ‘a’ and the character ‘z’”, which happens to correspond to the lower case letters in English
‘Only’ in the most commonly used character encodings. In EBCDIC (https://en.wikipedia.org/wiki/EBCDIC), the [a-z] range includes more than 26 characters.
That’s one of the reasons POSIX has character classes (https://en.wikipedia.org/wiki/Regular_expression#Character_c...). [:lower:] always gets you the lowercase characters in the encoding that the program uses.
Re: Regex Isn't Hard (2023)
#63> e.g. This pattern ([0-9][0-9]?[0-9]][.])+ matches one, two or three digits followed by a . and also matches repeated patterns of this. This wold match an IP address (albeit not strictly). I love regular expressions but one thing I've learned over the years is the syntax is dense enough that even people who are confident enough to start writing regex tutorials often can't write a regex that matches an IP address.
Shameless plug: My Regex engine (https://pkg.go.dev/gitea.twomorecents.org/Rockingcool/kleing...) has dedicated syntax for this kind of task.
\.\.\.
EDIT: formatting
Re: Regex Isn't Hard (2023)
#64[deleted]
Re: Regex Isn't Hard (2023)
#65Regex is much easier if you don't do it all at once. It's perfectly acceptable to, say, trim all the leading spaces, store the result in a temp variable, trim all the trailing spaces, store the result in a temp variable, remove all the hyphens. etc. etc.
Everyone tries to create the platonic ideal regex that does everything in one line.
Re: Regex Isn't Hard (2023)
#66I consider myself a reasonably competent senior engineer, and yet with regex this is what I have noticed:
Every time I need to write even the simplest regex, I can't seem to get it right the first time. I always need to struggle with it for a long time. Sometimes even using online tools takes me time to get it right. This happens every.single.time.
It baffles me to no end. I'm a pretty quick learner of pretty much everything I get into. I write the most sophisticated Typescript code you can imagine; I've written a small toy language; I've written biometric authentication drivers; I've written my own functional UI lib. But, I cannot master regex.
You can give me all the arguments about what is good about regex, but in my experience (which you can't argue with), it is a VERY badly designed API, and nothing will convince me otherwise. Regex is probably the worst thing ever in programming.
Re: Regex Isn't Hard (2023)
#67> e.g. This pattern ([0-9][0-9]?[0-9]][.])+ matches one, two or three digits followed by a . and also matches repeated patterns of this. This wold match an IP address (albeit not strictly). I love regular expressions but one thing I've learned over the years is the syntax is dense enough that even people who are confident enough to start writing regex tutorials often can't write a regex that matches an IP address.
^^^ this ^^^ I can’t understand my own regexes after a couple weeks - much less the ones I got the AI to write for me because I’m lazy or time constrained.
Re: Regex Isn't Hard (2023)
#68One can think of regex as very compact notation for writing text operations. It helps a lot.
The popular idea of them being write-only is obviously a joke, but it has some truth to it. On the good side, small code that needs to be rewritten is often better than large code that needs to be maintained.
Re: Regex Isn't Hard (2023)
#69[deleted]
Re: Regex Isn't Hard (2023)
#70I jump here just to say that non-greedy construction is valuable and not using them make expression harder to write and to understand.